1. Field of the Invention
The present invention relates to a wheel chair, and more particularly to a wheel chair capable of easily ascending or descending obstacles or stairs, and enabling a user to always have a stable posture.
2. Description of the Related Art
Generally, patients or handicapped persons who do not behave by the force of his/her will utilize a wheel chair to move or travel. Such wheelchairs include a wheel frame having a seating part allowing a user to keep a seating posture. The wheel frame is provided with a rear wheel of a relatively large diameter. The rear wheel may be manually driven by a hand of the user or automatically driven by a separate actuator. In addition, the wheel frame is provided at a front thereof with a front wheel for stably maintaining the wheel frame.
With the structure of the conventional wheelchair as described above, the wheels are only rotated by an axle or driving shaft. Accordingly, the wheel chair may move on a level ground or easily go over the obstacle of a restricted height, without difficulty. During moving on the sands or marshy ground, or going over a high obstacle (in particular, the stairs), there is a problem in that the wheel idles or does not go over the obstacle.
In case of moving on a slope, since the user leans corresponding to the inclination of the slope, the user may not maintain the stable seating posture.
In case of the automatic-type wheel chair utilizing the actuator or motor, when the wheel chair is manually driven in case it is out of order, since the user rotates the rear wheel by holding it, thereby requiring excessive power.
In addition, in case of reinforcing or improving the function of the wheel chair, since the number of components is increased, the cost is expensive and the weight is increased.